Conventionally, a collision determination apparatus that determines a collision of a vehicle with an acceleration sensor and activates an occupant protection apparatus, such as an airbag, is known. JP-A-2006-105598 (corresponding to US 2006/0065050 A1) discloses an occupant protection apparatus in which two uniaxial acceleration sensors are mounted on a wiring substrate in such a manner that axes of the acceleration sensors are perpendicular to each other so as to detect accelerations in a front-rear direction (an X-axis) and a right-left direction (a Y-axis) of the vehicle.
In the above-described collision determination apparatus, a connector to be coupled with a satellite sensor or an airbag ignition device is disposed. The position of the connector depends on the vehicle in which the collision determination apparatus is mounted. For example, the connector may be disposed on a side surface of a rear portion of the wiring substrate or the connector may be disposed on a side surface of a side portion of the wiring substrate. Thus, when the collision determination apparatus is attached to various vehicles, the collision determination apparatus needs to be rotated 90 degrees depending on the vehicles.
However, if the wiring substrate is only rotated 90 degrees, detection axes of the acceleration sensors change. Thus, in order to set the detection directions to the same directions even when the wiring substrate is rotated 90 degrees, another substrate having a wiring pattern in which a mounted portion of the acceleration sensors are rotated 90 degrees needs to be prepared. Thus, a cost for preparing at least two kinds of wiring substrate may be high.